English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We report a detailed study of a model Hamiltonian which exhibits a richinterplay of geometrical spin frustration, strong electronic correlations, andcharge ordering. The character of the insulating phase depends on the magnitudeof Delta/|t| and on the sign of t. We find a Mott insulator for Delta >> U >>|t|; a charge transfer insulator for U >> \Delta >> |t|; and a correlatedcovalent insulator for U >> \Delta ~ |t|. The charge transfer insulating stateis investigated using a strong coupling expansion. The frustration of thetriangular lattice can lead to antiferromagnetism or ferromagnetism dependingon the sign of the hopping matrix element, t. We identify the "ring" exchangeprocess around a triangular plaquette which determines the sign of the magneticinteractions. Exact diagonalization calculations are performed on the model fora wide range of parameters and compared to the strong coupling expansion. Theregime U >> \Delta ~ |t| and t<0 is relevant to Na05CoO2. The calculatedoptical conductivity and the spectral density are discussed in the light ofrecent experiments on Na05CoO2.

Electronic and magnetic properties of the ionic Hubbard model on the striped triangular lattice at 3/4 filling